Cystatin C as a predictor factor in patients with renal cell carcinoma treated by everolimus

Association between preoperative serum Cystatin-C levels and postsurgical oncological prognosis in patients with PRCC: A retrospective cohort study

OBJECTIVE

Cystatin-C (Cys-C) is a predictor of several malignancies. However, whether Cys-C levels predict prognosis in patients with papillary renal cell carcinoma (PRCC) remains uncertain. The aim of this study was to assess the correlation between Cys-C and clinical outcomes in patients with PRCC.

METHODS

The medical records of 137 patients with PRCC who underwent surgery at our institution from January 2008 to December 2020 were retrospectively analyzed. Data were divided into two subgroups based on cutoff values and the relationship between the Cys-C group and their clinical outcomes was assessed.

RESULTS

By the last follow-up, 62 patients had died of various causes, 53 of whom died from PRCC. Sixty patients suffered recurrence or metastasis during follow-up. Based on the cutoff value, the patients were divided into two groups: low Cys-C group (Cys-C < 1.25 mg/L, n = 92) and high Cys-C group (Cys-C ≥ 1.25 mg/L, n = 45). Pathological classification and serum Cys-C levels were shown to be independent prognostic factors affecting clinical outcomes, according to multivariate Cox regression analysis (p < 0.05). After adjusting the Cox proportional hazards model, the risk of death was elevated in the high Cys-C group. The results of the area under the curve for time-dependent receiver operating characteristics analysis indicated that Cys-C is a stable and reliable prognostic biomarker for predicting survival in patients with PRCC. Forest plots, constructed to better reflect the comparison of hazard ratios between the two groups, confirmed that Cys-C levels were significantly associated with worsening overall survival.

CONCLUSION

This study is the first to examine the relationship between preoperative serum Cys-C levels and prognostic overall survival in patients with PRCC. Cys-C may be a useful biomarker for preoperative screening of high-risk patients who may require adjuvant therapy.

Role of cystatin C in urogenital malignancy

Urogenital malignancy accounts for one of the major causes of cancer-related deaths globally. Numerous studies have investigated novel molecular markers in the blood circulation, tumor tissue, or urine in order to assist in the clinical identification of tumors at early stages, predict the response of therapeutic strategies, and give accurate prognosis assessment. As an endogenous inhibitor of lysosomal cysteine proteinases, cystatin C plays an integral role in diverse processes. A substantial number of studies have indicated that it may be such a potential promising biomarker. Therefore, this review was intended to provide a detailed overview of the role of cystatin C in urogenital malignancy.

Correlation of Measured and Estimated Creatinine Clearance in Hospitalized Elderly Patients: A Retrospective Cohort Study

Background: Accurate assessment of renal function is essential in hospitalized elderly patients. Few studies have examined the accuracy of Cockcroft-Gault (C-G) estimates of creatinine clearance (CrCl) compared with measured clearance in these patients. Objective: The objective of this study was to determine the correlation between C-G estimates of CrCl and measured CrCl in hospitalized elderly patients. Methods: This Institutional Review Board-approved, single-center retrospective observational cohort study included all patients who were 65 years and older admitted to our medical center in January to September 2018 with either an 8- or 24-hour urine collected during admission. The primary outcome was correlation, bias, and precision of C-G estimates of CrCl versus measured CrCl using Pearson correlation, Spearman linear regression, and Bland-Altman analysis. Outliers were determined using a cut-off of ±20%. Data are presented as median (interquartile range) or percentages. Results: A total of 108 urine collections from 90 unique patients were included in the study. The patients were 51% female, median age was 71 (68-77) years, and median body mass index was 26.6 (22.8-31) kg/m². Most collections were over 24 hours (66.7%), and 38% were performed while patients were in an intensive care unit. Median blood urea nitrogen (BUN) was 24.5 (17-36) mg/dL and median serum creatinine was 0.71 (0.55-1.09) mg/dL. The median C-G estimation was 75.4 (48.2-110.6) mL/min, and the median measured CrCl was 79.1 (38.1-99.5) mL/min, r ² = .56 (P < .001). Bland-Altman analysis showed large limits of agreement (-75.5-57.7 mL/min), with a bias of -8.9 and precision (standard deviation of bias) of 34 mL/min. Outliers were common, with 38% of C-G estimation values >120% of measured CrCl, and 18% of C-G estimates <80% of measured CrCl. Conclusions: Measured CrCl varied significantly from C-G estimates in hospitalized elderly patients. It is important to recognize characteristics of patients who may benefit from measurement of CrCl. Future studies should examine the impact of this variance on clinical outcomes.

ID1 As a Prognostic Biomarker and Promising Drug Target Plays a Pivotal Role in Deterioration of Clear Cell Renal Cell Carcinoma

Clear cell renal cell carcinoma (ccRCC) is one of the most common cancers in the world. Our aim is to identify prognostic biomarkers that contribute to the progression of early stage ccRCC and clarify the mechanism. Here, the mRNA microarray expression profile of ccRCC samples was obtained from Gene Expression Omnibus (GEO) (GSE68417). 62 differentially expressed genes (DEGs) were gained by R Studio, including 31 upregulated genes and 31 downregulated genes. Pathway enrichment analysis was performed in DAVID database. Then, the protein-protein interaction network was obtained through STRING database and visualized by Cytoscape. Subsequently, among the network, only inhibitor of DNA Binding 1 (ID1) was significant between low-grade and high-grade ccRCC patients in TCGA data set. After analysis of the corresponding clinical information in R Studio, it is shown that low ID1 expression correlated with poor survival, high probability of tumor metastasis, and relatively high serum calcium. Later, functional enrichment of ID1 in GeneMANIA uncovered that regulating DNA binding is a main characteristic of ID1 in ccRCC, which was validated by Kaplan-Meier curve of ID1 associated genes using KM plotter database and R Studio. Immune infiltration analysis performed by Tumor Immune Estimation Resource (TIMER) revealed that CD8+ T cells and macrophages were prognostic factors. Furthermore, Valproic acid was analyzed to be the most convinced target drug of ID1 identified by Comparative Toxicogenomics Database (CTD). Taken together, ID1, a biomarker of clinical outcome in early stage ccRCC patients, has the potential function of preventing deterioration in ccRCC progression and metastasis.

Cystatins in cancer progression: More than just cathepsin inhibitors

Cystatins are endogenous and reversible inhibitors of cysteine peptidases that are important players in cancer progression. Besides their primary role as regulators of cysteine peptidase activity, cystatins are involved in cancer development and progression through proteolysis-independent mechanisms. Mechanistic studies of cystatin function revealed that they affect all stages of cancer progression including tumor growth, apoptosis, invasion, metastasis and angiogenesis. Recently, the involvement of cystatins in the antitumor immune responses was reported. In this review, we discuss molecular mechanisms and clinical aspects of cystatins in cancer. Altered expression of cystatins in cancer resulting in harmful excessive cysteine peptidase activity has been a subject of several studies in order to find correlations with clinical outcome and therapy response. However, involvement in anti-tumor immune response and signaling cascades leading to cancer progression designates cystatins as possible targets for development of new anti-tumor drugs.